At first the Aramaic script was adopted for both the languages.

At first the Aramaic script was adopted for both the languages. Later, however, a change took place and certain Aramaic letters were put together in Pahlawi to form what later came to be known the Pahlawi script. The Orientalists did not fully grasp the significance of these subtle technical differences and they have been treating old Pahlawi and Dari as one language. Consequently, they have been employing the terms Northern Pahlawi or the Parthian Pahlawi for the later language.

In recent times, however, some of them have defined it as the Parthian language whereas Pahlawi itself has been referred to as the Southern or Sassanian Pahlawi.…